Drive one hour west of Broken Hill. Drive past the backdrop of Mad Max II, past feral goats and frantic emus. Drive down a dirt track, cross three cattle grids and you’ll reach Bush Heritage’s Boolcoomatta Station Reserve.
Bush Heritage bought the former sheep station in 2006. Boolcoomatta’s 63 000 hectares contains vegetation under-represented in Australia’s national reserve system.
It boasts chenopod (saltbush) shrublands, Mulga woodlands and ephemeral wetlands. Creek beds are lined by grand old river red gums; squat, twisted and pocketed with bird hollows.
But for the occasional waterhole, the creeks are dry; the average rainfall is 190mm. To the west stand the Olary Ranges, some of the oldest rocks in Australia.
A 10-day stay
Late in 2014 I spent 10 days on and around Boolcoomatta, surveying saltbush shrubland vegetation for my postgraduate research project. I'm now mid-way through a Master of Science (Botany) at the University of Melbourne.
My research question is: How can Bush Heritage improve the way in which it monitors changes in vegetation? And how can control sites be included in Bush Heritage’s ecological monitoring framework? My supervisor, Dr. David Duncan, and I are monitoring on four neighbouring properties: two sheep stations, a property under a mining lease and Bimbowrie Conservation Park (home of Yellow-footed Rock-wallabies).
The neighbouring property owners were helpful to the extreme: they provided maps of their fence-lines and pointed out where they saw changes in vegetation. Glen Norris, Boolcoomatta’s Reserve Manager, was invaluable: chatting with the neighbours, ferrying us to and from Broken Hill, and producing vegetation maps of artistic splendour. A big thank you to Dave Duncan, Jim Radford, Sandy Gilmore and Kurt Tschirner, for all of your help.
Dave and I set up a total of 23 monitoring points on neighbouring properties. Each point was a 50m transect*, marked at either end by star pickets.
We walked each transect and measured the height, length and species name of each saltbush plant.
We then used a 1m x 1m quadrat to look at the soil surface condition (the coverage of leaf litter, bare ground, plants, etc.). I have just started sorting through this data. So, in the meantime, here are 5 of my favourite plants from Boolcoomatta, plus a few shots of saltbushes, sunsets and the world’s friendliest emus.
* A transect is a path along which one counts and records occurrences of the species of study (e.g. plants).
** Quadrat sampling is a tool used in the study of ecology, especially biodiversity. In general, a series of squares (quadrats) of a set size are placed in a habitat of interest and the species within those quadrats are identified and recorded.
The desert spurge
Euphorbia tannensis ssp. eremophila
Aboriginal name: Ipi-ipi (Pitjantjatjara Yankunytjatjara)
I know a botanist shouldn’t pick floral favourites, but I have a real soft-spot for the Desert Spurge (aka Bottletree Caustic). The Desert Spurge is an annual or short-lived perennial forb, with a succulent-like stem. The fruits are green, rounded, and look, to my eyes, a little like kangaroo ticks. Aboriginal groups use the sap to decorate the body. It's largely ungrazed by stock: the poisonous white milky sap can ‘bring on diarrhoea and affect the ability to walk’.
The fringed violet
Aboriginal names: Tjutirangu, Warinkura (Pitjantjatjara Yankunytjatjara)
The fringed violet is a perennial herb and is found from Tasmania to the tropics. I can vouch for its wide distribution: I’ve now spotted fringed violets in arid South Australia, subtropical Queensland and on a rocky walk on Waiben (Thursday Island). Each flower lasts for a single day, opening in the morning and withering by the afternoon. It has tuberous, narrow bulb-like roots that are thought to hold water.
The pearl bluebush
Aboriginal names: Unavailable.
M. sedifolia is a perennial shrub with woolly stems, shiny pink and yellow flowers. Most impressively, it's very long-lived. The half-life of a M. sedifolia on Koonamore Reserve was estimated to be between 150 and 300 years!! I find this remarkable, considering most of the Pearl Bluebushes we encountered were around a metre tall.
The fruit-salad plant
Aboriginal name: Intiyanu (Pitjantjatjara Yankunytjatjara)
The fruit-salad plant is a short-lived perennial form with sticky stems and purple-to-pink flowers. I first saw/smelt P. sphacelatum a month ago at Trephina Nature Park, east of Alice Springs. When crushed, the leaves and mature flowers smell like sweet fruit salad: it’s other common name is apple bush. I’m particularly fond of its raspy flowers.
Aboriginal names: Munyunpa, Watara (Pitjantjatjara Yankunytjatjara)
And lastly, the visual feast that is Eremophila sturt